“It doesn’t have to happen,” President Obama said from the White House briefing room on Monday afternoon as signals from Capitol Hill grew more dire. He warned of significant economic consequences. “Let me repeat this: It does not have to happen.”

But a call from Obama to the Republican speaker of the House, John Boehner, did nothing to bring the sides together. And a series of closed-door meetings and proposals late into the night resulted mostly in name-calling.

The only measure signed into law Monday was one to pay soldiers during the shutdown, an effort by both parties to limit political damage. The Obama administration said that new health care marketplaces were set to launch on Tuesday, despite the impasse.

After weeks of squabbling that played out like a low-speed car crash, lawmakers had looked increasingly dispirited as the hours drew toward midnight. The closing question was the same as it had been all along: whether Boehner would break from the most conservative wing of his party and agree to let lawmakers vote on a bill to fund the government without gutting Obama’s health law, as Tea Party conservatives have insisted.

Such a bill would probably pass in the House with the help of Democrats and keep the government open through either mid-November or mid-December, depending on which version is used. But it could cost Boehner his job as speaker.

An effort by House Republican moderates to force Boehner’s hand by voting down a Republican amendment failed, drawing only 12 Republicans, Monday evening. It put on stark display the level of control the Tea Party members have over the House caucus, which has surprised even Senate Republicans.

“I don’t think there’s a good way out,” said Senator Jeff Flake of Arizona, one of several influential Republicans who had urged against the hard-line strategy employed by his colleagues in the House.

The staunch House conservatives continued to insist Monday, as they have for several months, that any measure to fund the federal government include provisions to delay, weaken, or kill the health law that they had campaigned against for three years. The House has voted more than 40 times to repeal the law, without success, because Democrats in the Senate and White House have pledged to protect it.

“One faction of one party in one house of Congress in one branch of government doesn’t get to shut down the entire government just to refight the results of an election,” Obama said Monday.

Just minutes after he spoke with Obama by phone, an animated Boehner took to the floor and showed that he would continue to side with the Tea Party wing and not retreat. He insisted he was acting in the best interests of the American people.

“It’s not about me. It’s not about Republicans here in Congress,” he said, noting that Obama had already delayed a requirement that employers provide health coverage. “How can we give waivers and breaks to all the big union guys out there ... and yet stick our constituents with a bill they don’t want and a bill they can’t afford?”

“We listen to the people that we represent, and we have a responsibility to act on their behalf,” said Representative Cathy McMorris Rodgers, a Washington State Republican who serves on Boehner’s leadership team.

It was not only constituents applying the pressure. All Republicans were well aware that their moves were under a glare of scrutiny from the Club for Growth, Senate Conservatives Fund, and other conservative interest groups that were prepared to slam them as “squishes” and endorse primary challengers unless they complied with the plans to use the government funding fight to battle the health law.

“The outside groups are scoring against it, agitating against it. That’s the problem,” said one Republican senator who opposed the strategy.

The White House and Senate Democrats — backed by polls showing most Americans would blame the GOP for a shutdown — said from the beginning that they would not negotiate over Obama’s signature first-term accomplishment. They called Tea Party Republicans hostage-takers, anarchists, and “banana Republicans.”

“With a bully, you cannot let them slap you around, because today they slap you five or six times,” majority leader Harry Reid, a Democrat, told reporters Monday. “Tomorrow it’s seven or eight times. We are not going to be bullied.”

The day began on a negative note and stayed that way, with little sign lawmakers could stop the march toward a shutdown dysfunction. The Democratic-controlled Senate, along party lines, quickly rejected a House measure Monday afternoon that would fund the government until mid-December only on the condition that the health law was delayed by a year and a medical device tax needed to fund part of it was repealed.

The result surprised no one. Last week, the Senate had already rejected another House plan that would have removed funding from the health law as a condition for keeping the government open.

After meeting for 90 minutes Monday, House Republicans came up with a third plan: delay, for one year, the law’s requirement that individuals purchase health insurance and remove employer insurance subsidies from members of Congress and their staffs. That plan too, was immediately doomed in the Senate, voted down on party lines.

“We are not going to mess with Obamacare, no matter what they do,” Reid said. “They’ve got to get a life.”

He and other Democrats said giving any ground in the fight would encourage Republicans to use fiscal deadlines as leverage over unrelated grievances.

Reid also rejected a late-night effort by Boehner to appoint an official negotiating committee, with minutes to go before the shutdown. Reid said Senate Democrats would not negotiate on a long-term funding plan unless the House Republicans first approved a six-week plan to keep government open.

The next fiscal deadline is mere weeks away, over raising the nation’s debt limit. A failure to act on that deadline, allowing the government to default on its debts, could do much more significant damage to the national economy than even a shutdown. And Republican insurgents have already signaled they plan to negotiate over that deadline as well.

“The debt ceiling is cataclysmic,” Reid said. “They are playing with fire.”

Senator Elizabeth Warren of Massachusetts stood with other Democrats to defend the health law, which is expected to provide insurance for millions of uninsured. She also criticized Republicans for including a measure in one of its proposals that would allow employers and insurers to opt out of contraceptive coverage based on moral objections.

“I will never let backward looking ideologues cut women’s access to birth control,” she said. “We’ve lived in that world and we’re not going back.”

Behind the scenes Monday, several Republican senators urged their House colleagues to end the fight and avoid a shutdown. But after another closed-door meeting, this one among Senate Republicans, the faces were glum.

“You’ve heard me many, many times. We will not repeal Obamacare and it’s just a matter of when we move on,” said Senator John McCain, the Arizona Republican. “As I say, I’ve seen the movie before. I know how it ends.”

There were clearly House Republicans who were not buying that argument. Even if a shutdown harmed the GOP, many House members come from strongly conservative districts where voters back the strategy and might punish them if they appeared to retreat or compromise.

“There’s a group that think that if we shut the government down, that the Senate and the White House are going to cave,” said Representative Devin Nunes, a California Republican, emerging from one of the closed-door meetings. “We could be in a sustained shutdown.”

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.

Thanks & Welcome to Globe.com

You now have unlimited access for the next two weeks.

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.